TABLE 1.

Proposed revised definition and diagnostic criteria for acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF)

Revised definition An acute, clinically significant respiratory deterioration characterised by evidence of new widespread alveolar abnormality

Revised diagnostic criteria

•Previous or concurrent diagnosis of IPF#

•Acute worsening or development of dyspnoea typically <1 month duration

•Computed tomography with new bilateral ground-glass opacity and/or consolidation superimposed on a background pattern consistent with usual interstitial pneumonia pattern¶

•Deterioration not fully explained by cardiac failure or fluid overload+

^#: If the diagnosis of IPF is not previously established, this criterion can be met by the presence of radiological and/or histopathological changes consistent with usual interstitial pneumonia pattern on the current evaluation. ^¶: If no previous computed tomography is available, the qualifier “new” can be dropped. ⁺: Events that are clinically considered to meet the definition of acute exacerbation of IPF but fail to meet all four diagnostic criteria owing to missing computed tomography data should be termed “suspected acute exacerbations”. Reprinted from [4], with permission from the publisher.